Processes for the preparation of pesticidal compounds

ABSTRACT

The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the following U.S. ProvisionalPatent Application Ser. No. 62/042,559, filed Aug. 27, 2014; Ser. No.62/001,928, filed May 22, 2014; and Ser. No. 61/892,132, filed Oct. 17,2013, the entire disclosures of these applications are hereby expresslyincorporated by reference into this application.

TECHNICAL FIELD

This application relates to efficient and economical synthetic chemicalprocesses for the preparation of pesticidal thioether and pesticidalsulfoxides. Further, the present application relates to certain novelcompounds necessary for their synthesis. It would be advantageous toproduce pesticidal thioether and pesticidal sulfoxides efficiently andin high yield from commercially available starting materials.

DETAILED DESCRIPTION

The following definitions apply to the terms as used throughout thisspecification, unless otherwise limited in specific instances.

As used herein, the term “alkyl” denotes branched or unbranchedhydrocarbon chains.

Unless otherwise indicated, the term “cycloalkyl” as employed hereinalone is a saturated cyclic hydrocarbon group, such as cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl.

The term “thio” as used herein as part of another group refers to asulfur atom serving as a linker between two groups.

The term “halogen” or “halo” as used herein alone or as part of anothergroup refers to chlorine, bromine, fluorine, and iodine.

The compounds and process of the present application are described indetail below.

In step a of Scheme 1, 3-hydrazinopyridine dihydrochloride is reactedwith glyoxylic acid to yield (E)-2-(2-(pyridin-3-yl)hydrazono)aceticacid (6a). The reaction can be done with or without an acid, it ispreferred, however, that an acid is used. For example, it is preferredthat hydrochloric acid (HCl) is used. This reaction may be conducted ina protic solvent, for example, water. This reaction may be conducted attemperatures from about 0° C. to about 30° C.

In step b of Scheme 1, compound (6a) is reacted with acrylonitrile and asource of chlorine to yield3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carbonitrile (6b).The chlorine source may be, for example, N-chlorosuccinimide (NCS). Thereaction is also conducted in the presence of an inorganic base,preferably metal carbonates, metal hydroxides, metal phosphates, ormetal hydrides, more preferably, potassium bicarbonate (KHCO₃). Thereaction is also conducted in a polar aprotic solvent, preferably, ethylacetate (EtOAc). This reaction may be conducted at temperatures fromabout −10° C. to about 30° C.

In step c of Scheme 1, compound (6b) undergoes dehydrocyanation to yield3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b). This reaction is conducted inthe presence of an organic or inorganic base that promotes thedehydrocyanation, such as, 1, 8-diazabicyclo-[5.4.0]undec-7-ene (DBU),1, 5-diazabicyclo [4.3.0] non-5-ene (DBN), or potassium hydroxide. Thereaction may be conducted in a polar solvent, such asN,N-dimethyl-formamide (DMF), ethanol (EtOH), or tetrahydrofuran (THF).This reaction may be conducted at temperatures from about −10° C. toabout 30° C.

In step d of Scheme 1, compound (5b) is nitrated with nitric acid(HNO₃), preferably in the presence of sulfuric acid (H₂SO₄) to yield3-(3-chloro-4-nitro-1H-pyrazol-1-yl)pyridine (5c). The nitration may beconducted at temperatures from about −10° C. to about 30° C.

In step e of Scheme 1, compound (5c) is reduced to yield3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine (5d). For example, compound(5c) may be reduced with iron in acetic acid (AcOH). Compound (5c) mayalso be reduced with iron and ammonium chloride (NH₄Cl). Alternatively,this reduction may be carried out using other techniques in the art, forexample, compound (5c) may be reduced using palladium on carbon in thepresence of hydrogen (H₂). This reaction may be conducted attemperatures from about −10° C. to about 30° C.

In step g of Scheme 1, 3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine (5d)is acylated with acetylating agents such as acetyl chloride or aceticanhydride, preferably acetic anhydride (Ac₂O) to yieldN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1c). Theacylation is conducted in the presence of a base, preferably aninorganic base, such as, sodium bicarbonate (NaHCO₃), and preferably, apolar solvent, such as ethyl acetate and/or tetrahydrofuran. Thisreaction may be conducted at temperatures from about −10° C. to about30° C.

In step h of Scheme 1,N-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1c) is reducedto yield 3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1d). Thereaction is conducted in the presence of a hydride source, preferablysodium borohydride (NaBH₄), and an acid source, such as a BrØnsted acidor a Lewis acid, preferably a Lewis acid, preferably borontrifluorideetherate (BF₃.Et₂O). It has been surprisingly discovered that the yieldof the reaction is affected by the quality of the borontrifluorideetherate (purchased from different suppliers, currently, Sigma Aldrichproduct number 175501 being preferred). This reaction may be conductedat temperatures from about −10° C. to about 70° C.

Alternatively, instead of steps g and h, in step f of Scheme 1,3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine (5d) is condensed withacetaldehyde followed by reduction of the imine intermediate to yield3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-4-amine (1d). The reactionmay be conducted with a hydride source such as sodium borohydride in apolar protic solvent, such as methanol (MeOH) at temperatures from about−10° C. to about 40° C.

In step i of Scheme 1,3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1d) is reacted withan activated carbonyl thioether, indicated as X¹C(═O)C₁-C₄-alkyl-S—R¹,to yield pesticidal thioether (1e). R¹ is selected from the groupconsisting of C₁-C₄-haloalkyl and C₁-C₄-alkyl-C₃-C₆-halocycloalkyl,preferably, R¹ is selected from CH₂CH₂CF₃ orCH₂(2,2-difluorocyclopropyl). X¹ is selected from Cl, OC(═O)C₁-C₄ alkyl,or a group that forms an activated carboxylic acid. When X¹ is Cl orOC(═O)C₁-C₄ alkyl the reaction may be conducted in the presence of abase preferably, sodium bicarbonate to yield pesticidal thioether (1e).When X¹ is Cl or OC(═O)C₁-C₄ alkyl the reaction may also be conducted inthe absence of a base to yield pesticidal thioether (1e). Alternatively,the reaction may be accomplished when X¹C(═O)C₁-C₄-alkyl-S—R is anactivated carboxylic acid activated by such reagents as2,4,6-tripropyl-trioxatriphosphinane-2,4,-trioxide (T₃P),carbonyldiimidazole (CDI), dicyclohexylcarbodiimide (DCC) or1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), preferably2,4,6-tripropyl-trioxatriphosphinane-2,4,-trioxide andcarbonyldiimidazole at temperatures from about 0° C. to about 80° C.;this reaction may also be facilitated with uronium or phosphoniumactivating groups such as0-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluroniumhexafluorophosphate (HATU) orbenzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate(PyBOP), in the presence of an amine base such as diisopropylethylamine(DIPEA) or triethylamine (TEA) in an polar aprotic solvent such asN,N-dimethylformamide, tetrahydrofuran or dichloromethane (CH₂Cl₂), attemperatures from about −10° C. to about 30° C. to form pesticidalthioethers (1e). Activated carbonyl thioethers, may be prepared fromX¹C(═O)C₁-C₄-alkyl-S—R¹, wherein X¹ is OH may be prepared by reactingthe corresponding ester thioether, indicated as X¹C(═O)C₁-C₄-alkyl-S—R¹wherein X¹ is OC₁-C₄-alkyl, with a metal hydroxide such as lithiumhydroxide (LiOH) in a polar solvent such as methanol or tetrahydrofuran.

Alternatively, X¹C(═O)C₁-C₄-alkyl-S—R¹, wherein X¹ is OH or OC₁-C₄-alkylmay be prepared by the photochemical free-radical coupling of3-mercaptopropionic acid and esters thereof with 3,3,3-trifluoropropenein the presence of 2,2-dimethoxy-2-phenylacetophenone initiator and longwavelength UV light in an inert organic solvent. While stoichiometricamounts of 3-mercaptopropionic acid or esters thereof and3,3,3-trifluoropropene are required, because of its low boiling point,excess 3,3,3-trifluoropropene is usually employed to compensate forroutine losses. From about 1 to about 10 mole percent initiator,2,2-dimethoxy-2-phenylacetophenone, is typically used, with about 5 molepercent being preferred. Long wavelength UV light is sometimes called“black light” and ranges from about 400 to about 365 nanometers. Thephotochemical coupling is conducted in an inert organic solvent. Typicalinert organic solvents must remain liquid to about −50° C., must remainrelatively inert to the free radical conditions and must dissolve thereactants at reaction temperatures. Preferred inert organic solvents arearomatic and aliphatic hydrocarbons like toluene. The temperature atwhich the reaction is conducted is not critical but usually is fromabout −50° C. to about 35° C. Lower temperatures, however, are betterfor increased selectivity. Initially, it is important to keep thetemperature below the boiling point of 3,3,3-trifluoropropene, i.e.,about −18 to about −16° C. In a typical reaction, the inert organicsolvent is cooled to less than about −50° C. and the3,3,3-trifluoropropene is bubbled into the solvent. The3-mercaptopropionic acid or esters thereof and2,2-dimethoxy-2-phenylacetophenone are added and a long wave function(366 nm) UVP lamp (4 watt) is turned on. After sufficient conversion of3-mercapto-propionic acid or esters thereof, the light is turned off andthe solvent removed.

3-((3,3,3-Trifluoropropyl)thio)propanoic acid may also be prepared bythe low temperature free-radical initiated coupling of3-mercaptopropionic acid with 3,3,3-trifluoropropene in the presence of2,2′-azobis(4-methoxy-2,4-dimethyl) valeronitrile (V-70) initiator attemperatures of about −50° C. to about 40° C. in an inert organicsolvent. While stoichiometric amounts of 3-mercaptopropionic acid and3,3,3-trifluoropropene are required, because of its low boiling point,excess 3,3,3-trifluoropropene is usually employed to compensate forroutine losses. From about 1 to about 10 mole percent initiator, V-70,is typically used, with about 5 mole percent being preferred. The lowtemperature free-radical initiated coupling is conducted in an inertorganic solvent. Typical inert organic solvents must remain liquid toabout −50° C., must remain relatively inert to the free radicalconditions and must dissolve the reactants at reaction temperatures.Preferred inert organic solvents are toluene, ethyl acetate, andmethanol. The temperature at which the reaction is conducted from about−50° C. to about 40° C. Initially, it is important to keep thetemperature below the boiling point of 3,3,3-trifluoropropene, i.e.,about −18 to about −16° C. The solution is cooled to less than about−50° C. and the 3,3,3-trifluoropropene is transferred into the reactionmixture. After stirring at room temperature for 24 hours, the reactionmixture is heated to about 50° C. for about 1 hour to decompose anyremaining V-70 initiator followed by cooling and solvent removal.

In step j of Scheme 1, thioether (1e) is oxidized with hydrogen peroxide(H₂O₂) in methanol to yield pesticidal sulfoxides (if).

3-(3-Chloro-1H-pyrazol-1-yl)pyridine (5b) may alternatively be preparedthrough the reaction pathway disclosed in Scheme 2.

In step a of Scheme 2, (E)-2-(2-(pyridin-3-yl)hydrazono)acetic acid (6a)is reacted with methyl acrylate in the presence of a chlorine sourcesuch N-chlorosuccinimide, an inorganic base, preferably metalcarbonates, metal hydroxides, metal phosphates, or metal hydrides, morepreferably potassium bicarbonate and a polar aprotic solvent,preferably, ethyl acetate, and addition of a sub-stoichiometric amountof water to yield methyl3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate (6c).This reaction may be conducted at temperatures from about −10° C. toabout 30° C.

In step b of Scheme 2, methyl3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate (6c) isoxidized with diammonium cerium (IV) nitrate (CAN) in water and polarsolvents such as tetrahydrofuran at temperatures from about 0° C. toabout 30° C. to yield methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d). It wassurprisingly discovered that the oxidation in step b can also proceedwith potassium permanganate (KMnO₄) as the oxidant in polar solventssuch as acetone at temperatures from about 0° C. to about 30° C.However, many standard oxidation procedures such as, for examplepotassium persulfate (K₂S₂O₈), iodine pentoxide (I₂O₅), copper oxide(CuO), and hydrogen peroxide were found to be inoperative.

In step c of Scheme 2, methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d) is saponifiedin the presence of an inorganic base, preferably metal hydroxides ortheir hydrates such as lithium hydroxide hydrate (LiOH.H₂O) in water anda polar solvent such as dioxane at temperatures from about 0° C. toabout 30° C. to yield 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylicacid (6e). Alternatively, this process can also be accomplished byhydrolysis by exposing methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d) to aconcentrated acid such as hydrochloric acid in water at temperaturesfrom about 30° C. to about 100° C.

In step d of Scheme 2,3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid (6e) isdecarboxylated in the presence of copper (II) oxide in polar solventssuch as N,N-dimethylformamide at temperatures from about 80° C. to about140° C. to yield 3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b). It wassurprisingly discovered that this decarboxylation only occurs in thepresence of copper (II) oxide. Several known decarboxylation agents fromthe literature such as, for example, hydrochloric acid (See alternatesynthetic route, Example 14), sulfuric acid, and palladium (II)trifluoroacetate/trifluoroacetic acid (Pd(TFA)₂/TFA) (See “CE-5”) didnot yield the desired product.

3-Chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1 d) may be preparedthrough the reaction pathway sequence disclosed in Scheme 3. In step d1,N-(3-chlorol-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1c) may bealkylated with ethyl bromide (EtBr) in the presence of a base, such assodium hydride (NaH), sodium tert-butoxide (NaOt-Bu), potassiumtert-butoxide (KOt-Bu), or sodium tert-amyloxide, in a polar aproticsolvent, such as tetrahydrofuran, at temperatures from about 20° C. toabout 40° C., over a period of time of about 60 hours to about 168hours, to yieldN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide (1c′). Ithas been discovered that use of an iodide additive, such as potassiumiodide (KI) or tetrabutylammonium iodide (TBAI) can decrease the timenecessary for the reaction to occur to about 24 hours. It has also beendiscovered that heating the reaction at about 50° C. to about 70° C. ina sealed reactor (to prevent loss of ethyl bromide) also decreases thereaction time to about 24 hours. In step d2,N-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide (1c′) maybe treated with hydrochloric acid in water at temperatures from about50° C. to about 90° C., to yield3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1d). The reactionpathway sequence disclosed in Scheme 3 may also be performed without theisolation ofN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide (1c′).

In step a of Scheme 4, 3-hydrazinopyridine-dihydrochloride is treatedwith a di-C₁-C₄ alkyl maleate such as diethyl maleate in a C₁-C₄aliphatic alcohol at a temperature of about 25° C. to about 100° C. inthe presence of an alkali metal C₁-C₄ alkoxide to provide pyrazolidinecarboxylate (10a). While stoichiometric amounts of3-hydrazinopyridine-1-dihydrochloride and di-C₁-C₄ alkyl maleate arerequired, it is often convenient to use about a 1.5 fold to about a 2fold excess of di-C₁-C₄ alkyl maleate. The cyclization is run in thepresence of an alkali metal C₁-C₄ alkoxide base such as sodium ethoxide.It is often convenient to use about a 2 fold to about a 5 fold excess ofbase. The cyclization is performed in a C₁-C₄ aliphatic alcohol such asethanol. It is most convenient that the alkoxide base and the alcoholsolvent be the same, for example, sodium ethoxide in ethanol.

In step b of Scheme 4, the pyrazolidine carboxylate (10a) may be treatedwith a chlorinating reagent in an inert organic solvent at a temperatureof about 25° C. to about 100° C. to provide chlorinated dihydropyrazolecarboxylate (10b). Suitable chlorinating reagents include phosphoryltrichloride and phosphorus pentachloride. Phosphoryl trichloride ispreferred. It is often convenient to use about a 1.1 fold to about a 10fold excess of the chlorinating reagent. The chlorination is performedin an organic solvent that is inert to the chlorinating reagent.Suitable solvents include nitriles such as acetonitrile. With phosphoryltrichloride as the chlorinating reagent, acetonitrile is a preferredsolvent.

In step c of Scheme 4, chlorinated dihydropyrazole carboxylate (10b) maytreated with an oxidant in an organic solvent at a temperature of about25° C. to about 100° C. to provide chlorinated pyrazole carboxylate(10c). Suitable oxidants include manganese (IV) oxide and sodiumpersulfate/sulfuric acid. It is often convenient to use about a 1.5 foldto about a 15 fold excess of oxidant. The oxidation is performed in anorganic solvent that is inert to the oxidant. Suitable solvents includenitriles such as acetonitrile. With manganese (IV) oxide (MnO₂) orsodium persulfate/sulfuric acid as the oxidant, acetonitrile is apreferred solvent.

In step d of Scheme 4, chlorinated pyrazole carboxylate (10c) may thenbe converted to the desired3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride(6e) by treatment in aqueous hydrochloric acid at a temperature of about25° C. to about 100° C. While stoichiometric amounts of reagents arerequired, it is often convenient to use an excess of reagents withrespect to the chlorinated pyrazole carboxylate. Thus, aqueoushydrochloric acid is used in large excess as the reaction medium.Alternatively, chlorinated pyrazole carboxylates may be saponified inthe presence of an inorganic base, preferably metal hydroxides or theirhydrates such as lithium hydroxide hydrate (LiOH—H₂O) in water and apolar solvent such as dioxane at temperatures from about 0° C. to about30° C. to yield 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid(6e).

In step e of Scheme 4,3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride(6e) is decarboxylated in the presence of copper (II) oxide in polarsolvents such as N,N-dimethylformamide at temperatures from about 80° C.to about 140° C. to yield 3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b). Itwas surprisingly discovered that this decarboxylation only occurs in thepresence of copper (II) oxide. Several known decarboxylation agents fromthe literature such as, for example, hydrochloric acid (See alternatesynthetic route, Example 14), sulfuric acid, and palladium (II)trifluoroacetate/trifluoroacetic acid (See “CE-5”) did not yield thedesired product.

Examples

The following examples are presented to better illustrate the processesof the present application.

COMPOUND EXAMPLES Example 1: (E)-2-((2-Pyridin-3-yl)hydrazono)aceticacid hydrochloride (6a)

Glyoxylic acid (50% in water) (54.5 mL, 494 mmol) and 1 N hydrochloricacid (˜100 mL) were added to 3-hydrazinopyridine dihydrochloride (60.0g, 330 mmol) and the reaction mixture was stirred at room temperature(about 22° C.) for 2 hours, at which point solid had started toprecipitate. The reaction was stirred for 24 hours, at which point LC/MSindicated that it was complete. The mixture was transferred to a flaskusing acetonitrile (1 L). The mixture was azeotroped three times fromacetonitrile (1 L). The resulting suspension was filtered to afford agreen solid which was washed with acetonitrile and vacuum dried at 40°C. to afford the desired product (68.3 g, 98%): mp 173-174° C.; ¹H NMR(400 MHz, DMSO-d₆) δ 12.55 (d, J=1.2 Hz, 1H), 8.61 (d, J=2.5 Hz, 1H),8.40 (dt, J=5.4, 0.9 Hz, 1H), 8.14 (ddd. J=8.7, 2.6, 1.2 Hz, 1H), 7.91(dd, J=8.7, 5.4 Hz, 1H), 7.43 (d, J=1.0 Hz, 1H); ¹³C NMR (101 MHz, DMSO)δ 164.29, 143.15, 133.15, 131.85, 127.97, 127.61, 126.30; ESIMS m/z 166([M+H]⁺).

Example 2:3-Chloro-1-(pyridine-3-yl)-4,5-dihydro-1H-pyrazole-5-carbonitrile (6b)

(E)-2-((2-Pyridin-3-yl)hydrazono)acetic acid hydrochloride (2.00 g, 9.42mmol) was stirred in ethyl acetate (47.1 mL). N-Chlorosuccinimide (2.36g, 19.3 mmol), acrylonitrile (1.85 mL, 28.3 mmol) and potassiumbicarbonate (2.86 g, 28.3 mmol) were added. Water (0.05 mL) was addedand the mixture was stirred at room temperature for 18 hours. Saturatedaqueous sodium chloride (brine, 50 mL) was added and the mixture wasfiltered through Celite®. The filter cake was washed with ethyl acetate(40 mL) and the layers were separated. The organic layers were combined,dried and concentrated to afford a residue. The resulting residue waspurified by flash column chromatography using 80-100% ethylacetate/hexanes as eluent to afford the desired product as an orangesolid (1.40 g, 57.5%): ¹H NMR (400 MHz, CDCl₃) δ 8.51 (dd, J=2.9, 0.7Hz, 1H), 8.33 (dd, J=4.7, 1.4 Hz, 1H), 7.51 (ddd, J=8.4, 2.9, 1.4 Hz,1H), 7.30 (ddd, J=8.5, 4.7, 0.8 Hz, 1H), 5.06 (dd, J=11.3, 5.9 Hz, 1H),3.64 (dd, J=17.4, 11.3 Hz, 1H), 3.51 (dd, J=17.4, 5.9 Hz, 1H); ¹³C NMR(101 MHz, CDCl₃) δ 143.34, 142.79, 140.11, 136.16, 123.92, 121.93,115.80, 51.39, 43.04; ESIMS m/z 207 ([M+H]⁺).

Example 3: 3-(3-Chloro-1H-pyrazol-1-yl)pyridine (5b)

3-Chloro-1-(pyridine-3-yl)-4,5-dihydro-1H-pyrazole-5-carbonitrile (0.500g, 2.42 mmol) was stirred in N,N-dimethylformamide (6.05 mL).1,8-Diazabicyclo[5.4.0]undec-7-ene (0.543 mL, 3.63 mmol) was added andthe dark mixture was stirred at room temperature overnight. LC/MSanalysis indicated that the reaction was complete. The mixture wasconcentrated and the dark oil was dissolved in ethyl acetate and washedwith 15% aqueous lithium chloride (LiCl) and brine. The organic portionwas dried over sodium sulfate (Na₂SO₄) and concentrated. The residue waspurified by flash column chromatography using ethyl acetate. The purefractions were concentrated and the residue was vacuum dried at 45° C.to yield the desired product as a white solid (450 mg, 93%): mp: 66-68°C.; ¹H NMR (400 MHz, CDCl₃) δ 8.93 (d, J=27 Hz, 1H), 8.57 (dd, J=4.8,1.4 Hz, 1H), 8.02 (ddd, J=8.3, 2.7, 1.5 Hz, 1H), 7.91 (d, J=2.6 Hz, 1H),7.47-7.34 (m, 1H), 6.45 (d, J=2.6 Hz, 1H); ¹³C NMR (101 MHz, CDCl₃) δ148.01, 142.72, 140.12, 135.99, 128.64, 126.41, 124.01, 108.0.

Alternate Synthetic Route to: 3-(3-chloro-1H-pyrazol-1-yl)pyridine(Scheme 2)

3-Chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride(1.00 g, 3.65 mmol) was stirred in N,N-dimethylformamide (10 mL).Copper(II) oxide (58.0 mg, 0.730 mmol) was added and the reaction washeated at 120° C. for 16 hours, at which point the reaction was ˜20%complete. Additional copper(II) oxide (112 mg, 1.46 mmol) was added andthe reaction was stirred for 5 hours, at which point the reaction wascomplete by thin layer chromatography (TLC) [Eluent: ethyl acetate]. Themixture was diluted with ammonium hydroxide (NH₄OH) and water andextracted with ethyl acetate. The organic layer was washed with 15%lithium chloride and concentrated to provide an orange solid. Theresidue was purified by flash column chromatography using ethyl acetateas eluent and the pure fractions were concentrated to afford the desiredproduct as a white solid (481 mg, 69.7%). The spectral characterizationwas in agreement with the product prepared previously.

Example 4: 3-(3-Chloro-4-nitro-1H-pyrazol-1-yl)pyridine (5c)

To a 100 mL round bottom flask was charged3-(3-chloro-1H-pyrazol-1-yl)pyridine (2.0 g, 11 mmol) and concentratedsulfuric acid (4 mL). This suspension was cooled to −5° C. and 2:1 (v/v)concentrated nitric acid/sulfuric acid (3 mL, prepared by adding theconcentrated sulfuric acid to a stirring and cooling solution of thenitric acid) was added dropwise at a rate such that the internaltemperature was maintained <15° C. The reaction was allowed to warm to20° C. and stirred for 18 hours. A sample of the reaction mixture wascarefully diluted into water, basified with 50% sodium hydroxide (NaOH)and extracted with ethyl acetate. Analysis of the organic layerindicated that the reaction was complete. The reaction mixture wascarefully added to ice cold water (100 mL) at <20° C. and basified with50% sodium hydroxide at <20° C. The resulting light yellow suspensionwas stirred for 2 hours and filtered. The filter cake was rinsed withwater (3×20 mL) and dried to afford an off-white solid (2.5 g,quantitative): mp 141-143° C.; ¹H NMR (400 MHz, DMSO-d₆) δ 9.86 (s, 1H),9.23-9.06 (m, 1H), 8.75-8.60 (m, 1H), 8.33 (ddd, J=8.4, 2.8, 1.4 Hz,1H), 7.64 (ddd, J=8.5, 4.7, 0.7 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ149.49, 140.75, 136.02, 134.43, 132.14, 131.76, 127.22, 124.31; EIMS m/z224 ([M]⁺).

Example 5: 3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine (5d)

To a 100 mL, 3-neck round bottom flask was charged3-(3-chloro-4-nitro-1H-pyrazol-1-yl)pyridine (2.40 g, 10.7 mmol), aceticacid (4 mL), ethanol (4.8 mL) and water (4.8 mL). The mixture was cooledto 5° C. and iron powder (2.98 g, 53.4 mmol) was added portionwise over˜15 minutes. The reaction was allowed to stir at 20° C. for 18 hours anddiluted to 50 mL with water. The mixture was filtered through Celite®and the filtrate was carefully basified with 50% sodium hydroxidesolution. The resulting suspension was filtered through Celite® and thefiltrate was extracted with ethyl acetate (3×20 mL). The organics weredried over sodium sulfate and concentrated to dryness to afford a tancolored solid, which was further dried under vacuum for 18 hours (2.2 g,quantitative): mp 145-147° C.; ¹H NMR (400 MHz, DMSO-d₆) δ 8.95 (dd,J=2.6, 0.8 Hz, 1H), 8.45 (dd, J=4.7, 1.4 Hz, 1H), 8.08 (ddd, J=8.4, 2.7,1.4 Hz, 1H), 7.91 (s, 1H), 7.49 (ddd, J=8.3, 4.7, 0.8 Hz, 1H), 4.43 (s,2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 146.35, 138.53, 135.72, 132.09,130.09, 124.29, 124.11, 114.09; EIMS m/z 194 ([M]⁺).

Alternate Synthetic Route to: 3-Chloro-1(pyridin-3-yl)-1H-pyrazol-4-amine

A suspension of 3-(3-chloro-4-nitro-1H-pyrazol-1-yl)pyridine (1.00 g,4.45 mmol) and palladium on carbon (10 wt %, 0.05 g, 0.467 mmol) inmethanol (20 mL) was purged with nitrogen (N2) three times, followed byhydrogen three times. The reaction was stirred at 20° C. under 40 psi ofhydrogen for 4 hours. After which time the reaction was purged withnitrogen three times and analyzed by thin layer chromatography [Eluent:10% methanol/dichloromethane], which indicated that the reaction wascomplete. The reaction mixture was filtered through a Celite® pad andthe pad was rinsed with methanol (2×10 mL). The filtrates wereconcentrated to dryness to afford a slightly pink solid (0.82 g, 95%).The spectral characterization was in agreement with the product preparedpreviously.

Alternate Synthetic Route to:3-(3-chloro-4-amino-1H-pyrazol-1-yl)pyridine (5d)

In a 250 mL 3-neck round bottom flask was added3-(3-chloro-4-nitro-1H-pyrazol-1-yl)pyridine (5.00 g, 21.8 mmol),ethanol (80 mL), water (40 mL), and ammonium chloride (5.84 g, 109mmol). The suspension was stirred under nitrogen stream for 5 minutesthen iron powder (4.87 g, 87.2 mmol) added. The reaction mixture washeated to reflux (˜80° C.) and held there for 4 hours. After 4 hours areaction aliquot taken showed by HPLC analysis the reaction had gone tofull conversion. Ethyl acetate (120 mL) and Celite® (10 g) were added tothe reaction mixture and let stir for 10 minutes. The black coloredsuspension was then filtered via a Celite® pad and the pad rinsed withethyl acetate (80 mL). The reaction mixture was washed with saturatedsodium bicarbonate (30 mL) and the organic layer was assayed. The assaygave (4.19 g, 99%) of product. The organic solvent was removed in vacuoto give a brown colored crude solid that was used without furtherpurification.

Example 6: N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1c)

A 100 mL three-neck round bottom flask was charged with3-chloro-1(pyridin-3-yl)-1H-pyrazol-4-amine (1.00 g, 5.14 mmol) andethyl acetate (10 mL). sodium bicarbonate (1.08 g, 12.9 mmol) was added,followed by dropwise addition of acetic anhydride (0.629 g, 6.17 mmol)at <20° C. The reaction was stirred at 20° C. for 2 hours to afford asuspension, at which point thin layer chromatography analysis [Eluent:ethyl acetate] indicated that the reaction was complete. The reactionwas diluted with water (50 mL) and the resulting suspension wasfiltered. The solid was rinsed with water (10 mL) followed by methanol(5 mL). The solid was further dried under vacuum at 20° C. to afford thedesired product as a white solid (0.804 g, 66%): mp 169-172° C.; ¹H NMR(400 MHz, DMSO-d₆) δ 9.84 (s, 1H), 9.05 (dd, J=2.8, 0.8 Hz, 1H), 8.82(s, 1H), 8.54 (dd, J=4.7, 1.4 Hz, 1H), 8.20 (ddd, J=8.4, 2.8, 1.4 Hz,1H), 7.54, (ddd, J=8.3, 4.7, 0.8 Hz, 1H), 2.11 (s, 3H); ¹³C NMR (101MHz, DMSO-d₆) δ 168.12, 147.46, 139.42, 135.46, 133.60, 125.47, 124.21,122.21, 120.16, 22.62; EIMS m/z 236 ([M]⁺).

Example 7: 3-Chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-4-amine (1d)

A 100 mL 3-neck round bottom flask was charged withN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (475 mg, 2.01mmol) and tetrahydrofuran (10 mL). borontrifluoride etherate (0.63 mL,5.02 mmol) was added and the mixture was stirred for 15 minutes to givea suspension. Sodium borohydride (228 mg, 6.02 mmol) was added and thereaction was heated at 60° C. for 4 hours, at which point thin layerchromatography analysis [Eluent: ethyl acetate, sample was prepared bytreatment of reaction mixture with hydrochloric acid, followed by sodiumbicarbonate basification and ethyl acetate extraction] indicated thatthe reaction was complete. Water (10 mL) and concentrated hydrochloricacid (1 mL) were added and the reaction was heated at 60° C. for 1 hour.The reaction mixture was cooled to room temperature and distilled toremove tetrahydrofuran. The mixture was neutralized with saturatedaqueous sodium bicarbonate to pH ˜8 to afford a suspension, which wasstirred for 1 hour and filtered. The filter cake was rinsed with water(10 mL) and dried under vacuum to afford a white solid (352 mg, 79%): mp93-96° C.; ¹H NMR (400 MHz, DMSO-d₆) δ 8.99 (d, J=2.7 Hz, 1H), 8.44 (dd,J=4.6, 1.4 Hz, 1H), 8.10 (ddd, J=8.4, 2.7, 1.4 Hz, 1H), 8.06 (s, 1H),7.50 (dd, J=8.4, 4.7 Hz, 1H), 4.63 (t, J=6.0 Hz, 1H), 3.06-2.92 (m, 2H),1.18 (t, J=7.1 Hz, 3H); ¹³C NMR (101 MHz, DMSO-d₆) δ 146.17, 138.31,135.81, 132.82, 130.84, 124.10, 123.96, 112.23, 40.51, 14.28; EIMS m/z222 ([M]⁺).

Alternate Synthetic Route to:3-Chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-4-amine (1d)

A 3-neck, 100 mL round bottom flask was charged with3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine (5d) (500 mg, 2.57 mmol)and methanol (5 mL). The mixture was stirred for 5 minutes to give aclear solution. Acetaldehyde (136 mg, 3.09 mmol) was added and thereaction was stirred at 20° C. for 6 hours. Sodium borohydride (194 mg,5.14 mmol) was added and the reaction was stirred at 20° C. for 1 hour,at which point thin layer chromatography analysis [Eluent: ethylacetate] indicated that some starting material remained and a majorproduct formed. The reaction mixture was quenched with water (10 mL) andconcentrated under reduced pressure to remove methanol. Ethyl acetate(10 mL) was added and the organic layer was concentrated to dryness. Theresidue was purified by flash column chromatography using 20-40% ethylacetate/hexanes as eluent. The fractions containing pure product werecombined and concentrated to afford a white solid (328 mg, 58%). Thespectral characterization was in agreement with the product preparedpreviously.

Alternate Synthetic Route to:3-Chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine Step 1.N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide (1c′)

To a 3-neck, 100-mL round bottom flask was chargedN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (5.00 g, 21.1mmol) and tetrahydrofuran (50 mL). Sodium tert-butoxide (3.05 g, 31.7mmol) was added (causing a temperature rise from 22° C. to 27.9° C.),followed by bromoethane (4.70 mL, 63.4 mmol). The reaction was stirredat 35° C. for 168 hours, at which point HPLC analysis indicated thatonly 2.9% (area under the curve, AUC) starting material remained. Thereaction mixture was concentrated to give a brown residue, which wasdiluted with ethyl acetate (50 mL) and water (50 mL). The aqueous layerwas extracted with ethyl acetate (4×50 mL) and the combined organicswere concentrated to give a brown residue. The residue was dissolved indichloromethane (2×10 mL) and purified by flash column chromatographyusing 60-100% ethyl acetate/hexanes as eluent. The fractions containingpure product were combined and concentrated to afford the title productas a yellow solid (4.20 g, 74%): ¹H NMR (400 MHz, CDCl₃) δ 8.98 (d,J=2.7, 0.8 Hz, 1H), 8.62 (dd, J=4.8, 1.4 Hz, 1H), 8.06 (ddd, J=8.3, 2.7,1.4 Hz, 1H), 8.00 (s, 1H), 7.47 (dd, J=8.3, 4.7 Hz, 1H), 3.71 (q, J=7.1Hz, 2H), 1.97 (s, 3H), 1.16 (t, J=7.2 Hz, 3H); ¹³C NMR (101 MHz, CDCl₃)δ 170.69, 148.56, 140.89, 139.95, 135.64, 126.22, 126.08, 124.86,124.09, 43.77, 22.27, 13.15; mp: 87-91° C.; ESIMS m/z 265 ([M+H]⁺).

Step 1. N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide(1c′) To a 3-neck, 100-mL round bottom flask was chargedN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1.66 g, 7.0mmol) and tetrahydrofuran (16 mL). Sodium tert-butoxide (0.843 g, 8.77mmol, 1.25 eq) and ethyl bromide (0.78 mL, 10.52 mmol, 1.5 eq) wereadded and the reactor was capped with a septa. The reaction was stirredat 58° C. for 24 hours, at which point HPLC analysis indicated that only1.97% starting material remained. The mixture was concentrated to give abrown residue, which was dissolved in water (20 mL) and ethyl acetate(20 mL). The aqueous layer was extracted with ethyl acetate (2×20 mL)and the combined organics were concentrated to dryness. The residue waspassed through a silica gel plug (40 g silica) and eluted with ethylacetate (200 mL). The filtrates were concentrated to dryness and furtherdried under vacuum at 20° C. to afford a yellow solid (1.68 g, 89%).Characterization matched sample prepared by previous method.

Step 1. N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide(1c′)

In a 125 mL 3-neck round-bottomed flask was addedN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (2.57 g, 9.44mmol), tetrahydrofuran (55 mL), and sodium tert-butoxide (1.81 g, 18.9mmol). The suspension was stirred for 5 minutes then ethyl bromide (1.41mL, 18.9 mmol), and tetrabutylammonium iodide (67 mg, 0.2 mmol) wereadded. The resulting gray colored suspension was then heated to 38° C.The reaction was analyzed after 3 hours and found to have gone to 81%completion, after 24 hours the reaction was found to have gone tocompletion. The reaction mixture was allowed to cool to ambienttemperature and quenched with ammonium hydroxide/formic acid (HCO₂H)buffer (10 mL). The mixture was then diluted with tetrahydrofuran (40mL), ethyl acetate (120 mL), and saturated sodium bicarbonate (30 mL).The layers were separated and the aqueous layer was extracted with ethylacetate (2×30 mL). The organic layers were combined and silica gel (37g) was added. The solvent was removed in vacuo to give a solid that waspurified using semi-automated silica gel chromatography (RediSep Silica220 g column; hexanes (0.2% triethylamine)/ethyl acetate, 40/60 to 0/100gradient elution system, flow rate 150 mL/minutes) to give, afterconcentration, an orange solid weighing (2.19 g, 88%)

Step 2. 3-Chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1d)

A solution ofN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide (1.8 g,6.80 mmol) in 1 N hydrochloric acid (34 mL) was heated at 80° C. for 18hours, at which point HPLC analysis indicated that only 1.1% startingmaterial remained. The reaction mixture was cooled to 20° C. andbasified with 50 wt % sodium hydroxide to pH>9. The resulting suspensionwas stirred at 20° C. for 2 hours and filtered. The filter cake wasrinsed with water (2×5 mL), conditioned for 30 minutes, and air-dried toafford an off-white solid (1.48 g, 95%): ¹H NMR (400 MHz, DMSO-d6) δ9.00 (dd, J=2.8, 0.8 Hz, 1H), 8.45 (dd, J=4.7, 1.4 Hz, 1H), 8.11 (ddd,J=8.4, 2.8, 1.4 Hz, 1H), 8.06 (d, J=0.6 Hz, 1H), 7.49 (ddd, J=8.4, 4.7,0.8 Hz, 1H), 4.63 (t, J=6.0 Hz, 1H), 3.00 (qd, J=7.1, 5.8 Hz, 2H), 1.19(t, J=7.1 Hz, 3H); ¹³C NMR (101 MHz, DMSO) δ 146.18, 138.31, 135.78,132.82, 130.84, 124.08, 123.97, 112.23, 40.51, 14.28; ESIMS 223([M+H]⁺).

Alternate Synthetic Route to:3-Chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine

To a 3-neck, 100-mL round bottom flask was chargedN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (5 g, 21.13 mmol)and tetrahydrofuran (50 mL). Sodium tert-butoxide (4.06 g, 42.3 mmol)was added (causing a temperature rise from 22° C. to 27.6° C.), followedby ethyl bromide (6.26 mL, 85 mmol). The reaction was stirred at 35° C.for 144 h at which point only 3.2% (AUC) starting material remained. Thereaction mixture was concentrated to give a brown residue, which wasdissolved in 1N hydrochloric acid (106 mL, 106 mmol) and heated at 80°C. for 24 hours, at which point HPLC analysis indicated that thestarting material had been consumed. The reaction was cooled to 20° C.and basified with 50% sodium hydroxide to pH>9. The resulting suspensionwas stirred at 20° C. for 1 hour and filtered, the filter cake wasrinsed with water (25 mL) to afford a brown solid (5.18 g). Theresulting crude product was dissolved in ethyl acetate and passedthrough a silica gel plug (50 g) using ethyl acetate (500 mL) as eluent.The filtrate was concentrated to dryness to afford a white solid (3.8 g,80%).

Example 8:N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)propanamide(Compound 8.6)

A 100 mL three-neck round bottom flask was charged with3-chloro-N-ethyl-1-(pyridine-3-yl)-1H-pyrazol-4-amine (5.00 g, 22.5mmol) and ethyl acetate (50 mL). Sodium bicarbonate (4.72 g, 56.1 mmol)was added, followed by dropwise addition of3-((3,3,3-trifluoropropyl)thio)propanoyl chloride (5.95 g, 26.9 mmol) at<20° C. for 2 hours, at which point HPLC analysis indicated that thereaction was complete. The reaction was diluted with water (50 mL)(off-gassing) and the layers separated. The aqueous layer was extractedwith ethyl acetate (20 mL) and the combined organic layers wereconcentrated to dryness to afford a light brown solid (10.1 g,quantitative). A small sample of crude product was purified by flashcolumn chromatography using ethyl acetate as eluent to obtain ananalytical sample: mp 79-81° C.; ¹H NMR (400 MHz, DMSO-d₆) δ 9.11 (d,J=2.7 Hz, 1H), 8.97 (s, 1H), 8.60 (dd, J=4.8, 1.4 Hz, 1H), 8.24 (ddd,J=8.4, 2.8, 1.4 Hz, 1H), 7.60 (ddd, J=8.4, 4.7, 0.8 Hz, 1H), 3.62 (q,J=7.2 Hz, 2H), 2.75 (t, J=7.0 Hz, 2H), 2.66-2.57 (m 2H), 2.57-2.44 (m,2H), 2.41 (t, J=7.0 Hz, 2H), 1.08 (t, J=7.1 Hz, 3H). EIMS m/z 406([M]⁺).

Alternate Synthetic Route to:N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)propanamide

A 20 mL vial was charged with 3-((3,3,3-trifluropropyl)thio)propanoicacid (0.999 g, 4.94 mmol) and acetonitrile (5 mL). Carbonyldiimidazole(0.947 g, 5.84 mmol) (off-gassing) and 1H-imidazole hydrochloride (0.563g, 5.39 mmol) were added and the reaction was stirred at 20° C. for 4hours. 3-Chloro-N-ethyl-1-(pyridine-3-yl)-1H-pyrazol-amine (1.00 g, 4.49mmol) was added and the reaction was stirred at 75° C. for 42 hours, atwhich point HPLC analysis indicated that the conversion was 96%. Thereaction was cooled to 20° C. and concentrated to dryness. The residuewas purified by flash column chromatography using 80% ethylacetate/hexanes as eluent. Pure fractions were combined and concentratedto afford a light yellow solid (1.58 g, 86%).

Alternate Synthetic Route to:N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)propanamide

A solution of 3-((3,3,3-trifluoropropyl)thio)propanoic acid (2.18 g,10.8 mmol) and 3-chloro-N-ethyl-1-(pyridine-3-yl)-1H-pyrazol-amine (2.00g, 8.98 mmol) in ethyl acetate (16 mL) was cooled to 5° C.Diisopropylethylamine (5.15 mL, 29.6 mmol) was added dropwise at 0-5° C.over 30 minutes, followed by the addition of2,4,6-tripropyl-trioxatriphosphinane-2,4,-trioxide (4.00 g, 12.6 mmol)over 30 minutes at 0-5° C. The reaction was allowed to warm to 25-30° C.and stirred for 2 h. Upon reaction completion, the reaction mixture wascooled to 0-5° C. and quenched with water (12 mL). The layers wereseparated and the aqueous layer was extracted with ethyl acetate (30mL). The combined organic layers were concentrated to afford the desiredproduct as an oil (3.40 g, 94%).

Alternate Synthetic Route to:N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)propanamide

A 500 mL three-neck round bottom flask equipped with a stir bar,thermocouple, and nitrogen inlet was charged with3-chloro-N-ethyl-1-(pyridine-3-yl)-1H-pyrazol-amine (40.10 g, 91.7 wt %,165.1 mmol) and dichloromethane (199.1 g) making brown solution that wasendothermic on mixing. 3-((3,3,3-Trifluoropropyl)thio)propanoic acid(52.51 g, 70.0 wt %, 166.6 mmol) was added via syringe pump over 20minutes keeping the temperature below 30° C. The reaction went fromclear brown, to a mustard yellow slurry, to clear brown again over theaddition. After 1 hour, water (123.3 g) was added followed by 20 wt %sodium hydroxide (40.3 g). The pH was tested and was ˜13. After mixingfor 15 minutes the layers were allowed to separate over 50 minutes. Theaqueous layer (172.1 g) was treated with methanol (119.62 g) and 2 Nhydrochloric acid (28.20 g) giving a clear solution with pH ˜1 (320.0 g,0.1 wt % active, 0.3730 g active, 0.5% yield loss). The organic layer(278.1 g) was collected into a 500 mL flask for distillation. Adistillation head was attached to the 500 mL three neck round bottomedflask containing the organic layer. Approximately ⅔ of thedichloromethane was distilled then methanol was added with continueddistillation to remove residual dichloromethane and toluene. Thedistillation was continued until the toluene was less than 2.5 wt %. Anin pot yield was determined once the dichloromethane and toluene hadbeen exchanged with methanol (98.49 g methanol solution, 65.2 wt % byHPLC internal assay, 64.2 g active, 95.8% in process yield). Into theflask containing the solution of crudeN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)-propanamidewas added methanol (61.82 g) to get a 40 wt % solution and the flask wasequipped with a nitrogen inlet and overhead stirrer (banana blade) at227 RPM. Water (35.23 g) was added all at once and the solution wasseeded withN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)propanamide(96 mg) at 26.8° C. After stirring overnight at room temperature thedark brown slurry was cooled to 1° C. with and ice bath for 5 hours. Thesolids were isolated by filtration through a coarse glass frit.

The chocolate brown sandy solids were washed with cold 1:1 v:vmethanol/water (80 mL, 74.2 g). The wet cake (70.58 g) was allowed toair dry overnight to constant mass giving the titled compound as brownsolids (52.3 g, 94.1 wt % by HPLC internal standard assay, 49.23 gactive, 73.5% yield).

Example 9: 3-((3,3,3-Trifluoropropyl)thio)propanoic acid

A 100 mL, 3-neck round bottom flask was charged with 3-bromopropanoicacid (500 mg, 3.27 mmol) and methanol (10 mL), potassium hydroxide (KOH,403 mg, 7.19 mmol) was added, followed by 3,3,3-trifluoropropane-1-thiol(468 mg, 3.60 mmol). The mixture was heated at 50° C. for 4 hours, afterwhich it was acidified with 2 N hydrochloric acid and extracted withmethyl tert-butylether (MTBE, 2×10 mL). The organic layer wasconcentrated to dryness to afford a light yellow oil (580 mg, 88%): ¹HNMR (400 MHz, CDCl₃) δ 2.83 (td, J=7.1, 0.9 Hz, 2H), 2.78-2.64 (m, 4H),2.48-2.32 (m, 2H).

Alternate Synthetic Route to: 3-((3,3,3-Trifluoropropyl)thio)propanoicacid

A 100 mL stainless steel Parr reactor was charged withazobisisobutyronitrile (AIBN, 0.231 g, 1.41 mmol), toluene (45 mL),3-mercaptopropionic acid (3.40 g, 32.0 mmol), and octanophenone (526.2mg) as an internal standard and was purged and pressure checked withnitrogen. The reactor was cooled with dry ice and the3,3,3-trifluoropropene (3.1 g, 32.3 mmol) was condensed into thereactor. The ice bath was removed and the reactor heated to 60° C. andstirred for 27 hours. The internal yield of the reaction was determinedto be 80% by use of the octanophenone internal standard. The pressurewas released and the crude mixture removed from the reactor. The mixturewas concentrated by rotary evaporation and 50 mL of 10% sodium hydroxidewas added. The solution was washed with methyl tert-butylether (50 mL)then acidified to pH ˜1 with 6 N hydrochloric acid. The product wasextracted with 100 mL methyl tert-butylether, dried over magnesiumsulfate (MgSO₄), filtered, and concentrated to give the crude titledcompound as an oil (5.34 g, 26.4 mmol, 83%, 87.5 area % on GC): ¹H NMR(400 MHz, CDCl₃) δ 2.83 (td, J=7.1, 0.9 Hz, 2H), 2.76-2.64 (m, 4H),2.47-2.30 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 177.68, 125.91 (q, J=277.1Hz), 34.58 (q, J=28.8 Hz), 34.39, 26.63, 24.09 (q, J=3.3 Hz).; ¹⁹F NMR(376 MHz, CDCl₃) δ −66.49.

Alternate Synthetic Route to: 3-((3,3,3-Trifluoropropyl)thio)propanoicacid

A 250 mL three-neck round bottomed flask was charged with toluene (81mL) and cooled to <−50° C. with a dry ice/acetone bath.3,3,3-Trifluoropropene (10.28 g, 107.0 mmol) was bubbled into thesolvent and the ice bath was removed. 3-Mercaptopropionic acid (9.200 g,86.70 mmol) and 2,2-dimethoxy-2-phenylacetophenone (1.070 g, 4.170 mmol)was added and the long wave light (366 nm, 4 watt UVP lamp) was turnedon (Starting temperature: −24° C.). The reaction reached a hightemperature of 27.5° C. due to heat from the lamp. The reaction wasstirred with the black light on for 4 hours. After 4 hours the blacklight was turned off and the reaction concentrated by rotary evaporation(41° C., 6 mm Hg) giving a pale yellow oil (18.09 g, 51:1linear:branched isomer, 90 wt % linear isomer by GC internal standardassay, 16.26 g active, 93%). The crude material was dissolved in 10%sodium hydroxide w/w (37.35 g) and was washed with toluene (30 mL) toremove non-polar impurities. The aqueous layer was acidified to pH ˜2-3with hydrochloric acid (2 N, 47.81 g) and was extracted with toluene (50mL). The organic layer was washed with water (40 mL) and dried overmagnesium sulfate, filtered, and concentrated by rotary evaporationgiving a pale yellow oil (14.15 g, 34:1 linear:branched isomer, 94 wt %linear isomer by GC internal standard assay, 13.26 g active, 76%).

Alternative Synthesis of: 3-((3,3,3-Trifluoropropyl)thio)propanoic acid

A 100 mL stainless steel Parr reactor was charged with3-mercaptopropionic acid (3.67 g, 34.6 mmol), toluene (30.26 g), and2,2′-azobis(4-methoxy-2,4-dimethyl) valeronitrile (V-70, 0.543 g, 1.76mmol) and the reactor was cooled with a dry ice/acetone bath, purgedwith nitrogen, and pressure checked. 3,3,3-Trifluoropropene (3.20 g,33.3 mmol) was added via transfer cylinder and the reaction was allowedto warm to 20° C. After 24 hours, the reaction was heated to 50° C. for1 hour to decompose any remaining V-70 initiator. The reaction wasallowed to cool to room temperature. The solution was concentrated byrotary evaporation to provide the title compound (6.80 g, 77.5 wt %linear isomer by GC internal standard assay, 5.27 g active, 76%, 200:1linear:branched by GC, 40:1 linear:branched by fluorine NMR)

Example 10: Methyl-3-((3,3,3-trifluoropropyl)thio)propionate (Compound10.6)

A 100 mL stainless steel Parr reactor was charged withazobisisobutyronitrile (0.465 g, 2.83 mmol), toluene (60 mL) andmethyl-3-mercaptopropionate (7.40 g, 61.6 mmol) and was purged andpressure checked with nitrogen. The reactor was cooled with dry ice andthe 3,3,3-trifluopropopene (5.7 g, 59.3 mmol) was condensed into thereactor. The ice bath was removed and the reactor heated to 60° C. andstirred to 24 hours. The heat was turned off and the reaction left atroom temperature overnight. The mixture was removed from the reactor andconcentrated to a yellow liquid. The liquid was distilled by vacuumdistillation (2 Torr, 85° C.) and three fractions were collected:fraction 1 (1.3 g, 6.01 mmol, 10%, 70.9 area % by GC), fraction 2 (3.7g, 17.1 mmol, 29%, 87 area % by GC), and fraction 3 (4.9 g, 22.7 mmol,38%, 90.6 area % by GC): ¹H NMR (400 MHz, CDCl₃) δ 3.71 (s, 3H), 2.82,(td, J=7.3, 0.7 Hz, 2H), 2.75-2.68 (m, 2H), 2.63 (td, J=7.2, 0.6 Hz,2H), 2.47-2.31 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 172.04, 125.93 (q,J=277.2 Hz), 51.86, 34.68 (q, J=28.6 Hz), 34.39, 27.06, 24.11 (q, J=3.3Hz); ¹⁹F NMR (376 MHz, CDCl₃) δ −66.53.

Alternate Synthetic Route to:Methyl-3-((3,3,3-trifluoropropyl)thio)propionate

A 500 mL three-neck round bottomed flask was charged with toluene (200mL) and cooled to <−50° C. with a dry ice/acetone bath.3,3,3-Trifluoropropene (21.8 g, 227 mmol) was condensed into thereaction by bubbling the gas through the cooled solvent and the ice bathwas removed. Methyl 3-mercaptopropionate (26.8 g, 223 mmol) and2,2-dimethoxy-2-phenylacetophenone (2.72 g, 10.61 mmol) were added and aUVP lamp (4 watt) that was placed within 2 centimeters of the glass wallwas turned on to the long wave function (366 nanometers). The reactionreached 35° C. due to heat from the lamp. After 4 hours, all of thetrifluoropropene was either consumed or boiled out of the reaction. Thelight was turned off and the reaction stirred at room temperatureovernight. After 22 hours, more trifluoropropene (3.1 g) was bubbledthrough the mixture at room temperature and the light was turned on foran additional 2 hours. The reaction had converted 93% so no moretrifluoropropene was added. The light was turned off and the mixtureconcentrated on the rotovap (40° C., 20 torr) giving a yellow liquid(45.7 g, 21.3:1 linear: branched isomer, 75 wt % pure linear isomerdetermined by a GC internal standard assay, 34.3 g active, 71% in potyield).

Alternate Synthetic Route to:Methyl-3-((3,3,3-trifluoropropyl)thio)propionate

A 100 mL stainless steel Parr reactor was charged with methyl3-mercaptopropionate (4.15 g, 34.5 mmol), toluene (30.3 g), and2,2′-azobis(4-methoxy-2,4-dimethyl) valeronitrile (V-70, 0.531 g, 1.72mmol) and the reactor was cooled with a dry ice/acetone bath, purgedwith nitrogen, and pressure checked. 3,3,3-Trifluoropropene (3.40 g,35.4 mmol) was added via transfer cylinder and the reaction was allowedto warm to 20° C. After 23 hours the reaction was heated to 50° C. for 1hour to decompose any remaining V-70 initiator. The reaction was allowedto cool to room temperature. The solution was concentrated to providethe title compound (7.01 g, 66%, 70.3 wt % linear isomer by GC internalstandard assay, 4.93 g active, 66%, 24:1 linear:branched by GC, 18:1linear:branched by fluorine NMR)

Example 11:N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)sulfoxo)propanamide(Compound 11.6)

N-(3-Chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)propanamide (57.4 g, 141 mmol) was stirred in methanol (180 mL). To theresulting solution was added hydrogen peroxide (43.2 mL, 423 mmol)dropwise using a syringe. The solution was stirred at room temperaturefor 6 hours, at which point LCMS analysis indicated that the startingmaterial was consumed. The mixture was poured into dichloromethane (360mL) and washed with aqueous sodium carbonate (Na₂CO₃). The organic layerwas dried over sodium sulfate and concentrated under reduced pressure toprovide a thick yellow oil. The crude product was purified by flashcolumn chromatography using 0-10% methanol/ethyl acetate as eluent. Thepure fractions were combined and concentrated to afford the desiredproduct as an oil (42.6 g, 68%): ¹H NMR (400 MHz, DMSO-d₆) δ 9.09 (dd,J=2.8, 0.7 Hz, 1H), 8.98 (s, 1H), 8.60 (dd, J=4.7, 1.4 Hz, 1H), 8.24(ddd, J=8.4, 2.7, 1.4 Hz, 1H), 7.60 (ddd, J=8.4, 4.7, 0.8 Hz, 1H), 3.61(q, J=7.4, 7.0 Hz, 2H), 3.20-2.97 (m, 2H), 2.95-2.78 (m, 2H), 2.76-2.57(m, 2H), 2.58-2.45 (m, 2H), 1.09 (t, J=7.1 Hz, 3H); ESIMS m/z 423([M+H]⁺).

Example 12: Methyl3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate (6c)

(E)-2-(2-(Pyridin-3-yl)hydrazono)acetic acid hydrochloride (13.6 g, 64.1mmol) was stirred in ethyl acetate (250 mL). N-chlorosuccinimide (17.9g, 131 mmol) was added and the reaction stirred for 10 minutes. Methylacrylate (35.2 mL, 385 mmol) was added followed by addition of potassiumbicarbonate (19.4 g, 192 mmol). Water (0.05 mL) was added and themixture stirred at 18° C. The reaction temperature rose from 18 to 21°C. over 1 hour and the reaction was stirred for 20 hours. Water (300 mL)and saturated aqueous sodium carbonate (˜100 mL) were added. The mixturewas filtered through Celite® and the filtrate was extracted with ethylacetate (2×500 mL). The organic layers were dried and concentrated. Theresidue was purified by flash column chromatography using 50-100% ethylacetate/hexanes as eluent to afford the desired product as an orange oil(10.1 g, 62.5%): ¹H NMR (400 MHz, CDCl₃) δ 8.30 (dd, J=2.9, 0.7 Hz, 1H),8.18 (dd, J=4.7, 1.4 Hz, 1H), 7.38 (ddd, J=8.4, 2.9, 1.4 Hz, 1H), 7.19(ddd, J=8.5, 4.7, 0.7 Hz, 1H), 4.81 (dd, J=12.4, 6.9 Hz, 1H), 3.79 (s,3H), 3.56 (dd, J=17.8, 12.4 Hz, 1H), 3.34 (dd, J=17.8, 6.9 Hz, 1H);ESIMS m/z 240 ([M+H]⁺).

Example 13: Methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate(6d)

Methyl 3-chloro-1-(pyridine-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate(2.63 g, 11.0 mmol) was stirred in tetrahydrofuran (50 mL) and water (50mL) at 0° C. diammonium cerium (IV) nitrate (15.0 g, 27.4 mmol) wasadded in portions and the reaction was stirred at room temperature for18 hours. thin layer chromatography analysis indicated that the startingmaterial was consumed. The mixture was extracted with ethyl acetate(2×300 mL) and the organic layers were dried and concentrated. Theresidue was purified by flash column chromatography using 50-100% ethylacetate/hexanes as eluent. The pure fractions were concentrated toprovide the desired product as a yellow solid (1.50 g, 52%): mp 99-102°C.; ¹H NMR (400 MHz, DMSO-d₆) δ 9.00 (dd, J=2.5, 0.7 Hz, 1H), 8.83 (dd,J=5.2, 1.5 Hz, 1H), 8.35 (ddd, J=8.3, 2.5, 1.4 Hz, 1H), 7.83 (ddd,J=8.3, 5.2, 0.7 Hz, 1H), 7.35 (s, 1H), 3.78 (s, 3H); ¹³C NMR (101 MHz,CDCl₃) δ 158.34, 149.90, 146.89, 141.39, 136.09, 134.77, 133.30, 123.14,112.01, 52.53; ESIMS m/z 238 ([M+H]⁺).

Alternate Synthetic Route to: Methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate

Methyl 3-chloro-1-(pyridine-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate(0.500 g, 2.09 mmol) was stirred in acetone (10 mL). potassiumpermanganate (0.330 g, 2.09 mmol) was added in one portion and thereaction was stirred at room temperature overnight, at which point thinlayer chromatography analysis (70% ethyl acetate/hexanes) indicated thatthe reaction was <50% complete. Additional potassium permanganate (520mg, 3.29 mmol,) was added and the reaction was stirred for an additional4 hours. The mixture was filtered and concentrated and the residue waspartitioned between ethyl acetate and water. The organic portion wasdried over sodium sulfate, filtered, and concentrated. The residue waspurified flash column chromatography using 80-100% ethyl acetate/hexanesas eluent to provide the desired product as a white solid (180 mg 36%).

Example 14: 3-Chloro-1-(pyridine-3-yl)-1H-pyrazole-5-carboxylic acidhydrochloride (6e)

Methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (3.83 g, 16.1mmol) was stirred in dioxane (53.7 mL). The orange suspension was heateduntil a solution was achieved. Lithium hydroxide hydrate (1.01 g, 24.2mmol) in water (26.9 mL) was added to afford a darker red solution. Thereaction was stirred at room temperature for 1 hours, at which pointLCMS showed the corresponding acid to be the major product. The orangemixture was concentrated to dryness and the residue was mixed with 4 Nhydrochloric acid in dioxane (100 mL). The suspension was heated toreflux for 1 hour and allowed to cool to room temperature. The resultingsuspension was filtered and the filter cake was rinsed with dioxane. Thesolid was vacuum dried at 50° C. to afford the desire product as a whitesolid (4.00 g, 91%): mp 244-246° C.; ¹H NMR (400 MHz, DMSO-d₆) δ 9.00(dd, J=2.5, 0.7 Hz, 1H), 8.82 (dd, J=5.2, 1.4 Hz, 1H), 8.35 (ddd, J=8.3,2.4, 1.4 Hz, 1H), 7.85 (ddd, J=8.3, 5.2, 0.7 Hz, 1H), 7.25 (s, 1H); ¹³CNMR (101 MHz, DMSO-d₆) δ 158.71, 146.00, 143.44, 140.36, 137.00, 136.83,125.19, 111.71; ESIMS m/z 224 ([M+H]⁺).

Alternate Synthetic Route to:3-Chloro-1-(pyridine-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride

Methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (1.5 g, 6.0mmol) was stirred in concentrated hydrochloric acid (25 mL). Thereaction mixture was heated at reflux to afford a yellow solution. Afterheating overnight a solid had precipitated, and LCMS analysis of themixture indicated that the reaction was complete. The mixture wasallowed to cool to room temperature and dioxane (50 mL) was added. Themixture was concentrated to dryness. acetonitrile (50 mL) was added andthe resulting mixture was concentrated. The residue was vacuum dried at40° C. to afford the desired product as a yellow solid (1.6 g, 97%).

Alternate Synthetic Route to:3-Chloro-1-(pyridine-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride

A 3-neck round bottomed flask (100 mL) was charged with ethyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (0.200 g, 0.795mmol) and hydrochloric acid (37%, 4 mL). The reaction was heated at 90°C. for 18 hours and allowed to cool to 20° C. Dioxane (5 mL) was addedto the resulting suspension and was concentrated to dryness. Dioxane (5mL) was added and the suspension was concentrated again to afford awhite solid. Dioxane (5 mL) was added and the resulting suspension wasstirred for 1 hour at 20° C. The solid was filtered and the solid wasrinsed with dioxane (2 mL). The filter cake was dried under vacuum at20° C. to afford the title compound as a white solid (0.218 g, 100%): ¹HNMR (400 MHz, DMSO-d₆) δ 9.05 (dd, J=2.5, 0.7 Hz, 1H), 8.84 (dd, J=5.3,1.4 Hz, 1H), 8.41 (ddd, J=8.3, 2.5, 1.4 Hz, 1H), 7.88 (ddd, J=8.3, 5.2,0.7 Hz, 1H), 7.26 (s, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 158.71, 146.00,143.44, 140.36, 137.76, 137.00, 136.83, 125.19, 111.71.

Example 15: 3-((3,3,3-Trifluoropropyl)thio)propanoyl chloride

A dry 5 L round bottom flask equipped with magnetic stirrer, nitrogeninlet, reflux condenser, and thermometer, was charged with3-((3,3,3-trifluoropropyl)thio)propanoic acid (188 g, 883 mmol) indichloromethane (3 L). Thionyl chloride (525 g, 321 mL, 4.42 mol) wasthen added dropwise over 50 minutes. The reaction mixture was heated toreflux (about 36° C.) for 2 hours, then cooled to room temperature.Concentration under vacuum on a rotary evaporator, followed bydistillation (40 Torr, product collected from 123-127° C.) gave thetitle compound as a clear colorless liquid (177.3 g, 86%): ¹H NMR (400MHz, CDCl₃) δ 3.20 (t, J=7.1 Hz, 2H), 2.86 (t, J=7.1 Hz, 2H), 2.78-2.67(m, 2H), 2.48-2.31 (m, 2H); ¹⁹F NMR (376 MHz, CDCl₃) δ −66.42, −66.43,−66.44, −66.44.

Example 16: 3-(((2,2-Difluorocyclopropyl)methyl)thio)propanoic acid

Powdered potassium hydroxide (423 mg, 7.54 mmol) and2-(bromomethyl)-1,1-difluorocyclopropane (657 mg, 3.84 mmol) weresequentially added to a stirred solution of 3-mercaptopropanoic acid(400 mg, 3.77 mmol) in methanol (2 mL) at room temperature. Theresulting white suspension was stirred at 65° C. for 3 hours andquenched with 1N aqueous hydrochloric acid and diluted with ethylacetate. The organic phase was separated and the aqueous phase extractedwith ethyl acetate (2×50 mL). The combined organic extracts were driedover magnesium sulfate, filtered and concentrated in vacuo to give thetitle molecule as a colorless oil (652 mg, 84%): IR (KBr thin film)3025, 2927, 2665, 2569, 1696 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 2.85 (t,J=7.0 Hz, 2H), 2.82-2.56 (m, 4H), 1.88-1.72 (m, 1H), 1.53 (dddd, J=12.3,11.2, 7.8, 4.5 Hz, 1H), 1.09 (dtd, J=13.1, 7.6, 3.7 Hz, 1H); ESIMS m/z195.1 ([M−H]⁻).

Example 17: 3-(((2,2-Difluorocyclopropyl)methyl)thio)propanoyl chloride

In a 3 L 3-neck round bottomed-flask equipped with an overhead stirrer,a temperature probe, and addition funnel and an nitrogen inlet wascharged with 3-(((2,2-difluorocyclopropyl)methyl)thio)propanoic acid(90.0 g, 459 mmol) that was immediately taken up in dichloromethane (140mL) with stirring. At room temperature, thionyl chloride (170 mL, 2293mmol) in dichloromethane (100 mL) was added drop-wise with stirring. Thereaction mixture was heated to 40° C. and heated for 2 hours. Thereaction was determined to be complete by 1H NMR (An aliquot of thereaction mixture was taken, and concentrated down via rotaryevaporator). The reaction was allowed to cool to room temperature andthe mixture was transferred to a dry 3 L round-bottom and concentratedvia the rotary evaporator. This resulted in 95 g of a honey-colored oil.The contents were gravity filtered through paper and the paper rinsedwith diethyl ether (10 mL). The rinse was added to the flask. This gavea clear yellow liquid. The liquid was placed on a rotary evaporator toremove the ether. This gave 92.4 g of a yellow oil. The oil wasKugelrohr distilled (bp 100-110° C./0.8-0.9 mm Hg) to provide the titlecompound as a colorless oil (81.4 g, 81%): ¹H NMR (400 MHz, CDCl₃) δ3.27-3.12 (m, 2H), 2.89 (t, J=7.1 Hz, 2H), 2.67 (ddd, J=6.8, 2.6, 1.0Hz, 2H), 1.78 (ddq, J=13.0, 11.3, 7.4 Hz, 1H), 1.64-1.46 (m, 1H), 1.09(dtd, J=13.2, 7.7, 3.7 Hz, 1H).

Example 18: Ethyl 5-oxo-2-(pyridin-3-yl)pyrazolidine-3-carboxylate(Compound 18.6)

A 4-neck round bottomed flask (250 mL) was charged with sodium ethoxide(21 wt % in ethanol, 56 mL, 192 mmol).3-Hydrazinopyridine-dihydrochloride (10.0 g, 55.0 mmol) was added,causing an exotherm from 20° C. to 32° C. The reaction was allowed tocool to 20° C. and diethyl maleate (13.4 mL, 82.0 mmol) was added, andthe reaction was heated at 60° C. for 3 hours. The reaction was cooledto 20° C. and quenched with acetic acid. The reaction mixture wasdiluted with water (100 mL) and extracted with ethyl acetate (3×100 mL).The combined organics were concentrated to dryness and the residue waspurified by flash column chromatography using ethyl acetate as eluent tothe title compound as a blue oil (6.60 g, 51%):

¹H NMR (400 MHz, DMSO-d₆) δ 10.40 (s, 1H), 8.40-8.26 (m, 1H), 8.19 (dd,J=4.4, 1.6 Hz, 1H), 7.47-7.21 (m, 2H), 4.77 (dd, J=9.8, 2.1 Hz, 1H),4.22 (qd, J=7.1, 1.7 Hz, 2H), 3.05 (dd, J=17.0, 9.8 Hz, 1H), 1.99 (s,1H), 1.25 (t, J=7.1 Hz, 3H); ¹³C NMR (101 MHz, DMSO-d₆) δ 170.37,146.60, 142.60, 137.28, 123.54, 121.94, 65.49, 61.32, 32.15, 20.72,13.94; ESIMS m/z 236 ([M+H]⁺).

Example 19: Ethyl3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate(Compound 19.6)

A 3-neck round bottomed flask (100 mL) was charged with ethyl5-oxo-2-(pyridin-3-yl)pyrazolidine-3-carboxylate (8.50 g, 36.1 mmol) andacetonitrile (40 mL). Phosphoryl trichloride (4.05 mL, 43.4 mmol) wascharged and the reaction was heated at 60° C. for 2 hours. The reactionwas cooled to 20° C. and water (100 mL) was added. Sodium carbonate wasadded to adjust pH to 8 and the mixture was extracted with ethyl acetate(3×100 mL). The organic layers were concentrated to dryness and theresidue was purified by flash column chromatography using 30-80% ethylacetate/hexanes as eluent to provide the title compound as a yellow oil(7.30 g, 79%): ¹H NMR (400 MHz, CDCl₃) δ 8.30 (dd, J=2.9, 0.8 Hz, 1H),8.17 (dd, J=4.7, 1.4 Hz, 1H), 7.38 (ddd, J=8.4, 2.8, 1.4 Hz, 1H), 7.18(ddd, J=8.4, 4.7, 0.7 Hz, 1H), 4.79 (dd, J=12.4, 6.9 Hz, 1H), 4.24 (qd,J=7.1, 1.1 Hz, 2H), 3.55 (dd, J=17.7, 12.4 Hz, 1H), 3.33 (dd, J=17.8,6.9 Hz, 1H), 1.25 (t, J=7.1 Hz, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 169.65,141.90, 141.33, 141.09, 135.13, 123.53, 120.37, 62.89, 62.35, 42.45,14.03; ESIMS m/z 254 ([M+H]⁺).

Example 20: Ethyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate

A 3-neck round bottomed flask (100 mL) was charged with ethyl3-chloro-1-(pyridin-3-yl)-1H-dihydropyrazole-5-carboxylate (2.00 g, 7.88mmol) and acetonitrile (20 mL). Manganese (IV) oxide (3.43 g, 39.4 mmol)was added, causing an exotherm from 20° C. to 21° C. The reaction wasstirred at 60° C. for 18 hours. Additional manganese (IV) oxide (3.43 g,39.4 mmol) was added and the reaction was stirred at 80° C. for 6 hours.The mixture was filtered through a Celite® pad and the pad was rinsedwith ethyl acetate (20 mL). The combined filtrates were concentrated todryness and the residue was purified by flash column chromatographyusing 10-60% ethyl acetate/hexanes. The pure fractions were concentratedto dryness to afford a white solid after drying (1.84 g, 93%): ¹H NMR(400 MHz, CDCl₃) δ 8.75-8.64 (m, 2H), 7.79 (ddd, J=8.2, 2.6, 1.5 Hz,1H), 7.42 (ddd, J=8.2, 4.8, 0.8 Hz, 1H), 6.98 (s, 1H), 4.27 (q, J=7.1Hz, 2H), 1.27 (t, J=7.1 Hz, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 157.90,149.88, 147.01, 141.41, 136.24, 135.27, 133.34, 123.11, 111.97, 61.87,13.98; ESIMS m/z 252 ([M+H]⁺).

Alternate Synthetic Route to: Ethyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate

A vial (20 mL) was charged with ethyl3-chloro-1-(pyridin-3-yl)-1H-dihydropyrazole-5-carboxylate (0.500 g,1.97 mmol) and acetonitrile (5 mL). Sodium persulfate (0.799 g, 2.96mmol) was added, followed by sulfuric acid (0.733 g, 7.88 mmol)(Exotherm!). The reaction was heated at 60° C. for 18 hours. Thereaction was cooled to 20° C. and poured into water (20 mL). The mixturewas basified with sodium carbonate to pH 9 and extracted with ethylacetate (2×20 mL). The organic layers were concentrated to a residue,which was purified by flash column chromatography using 50% ethylacetate/hexanes as eluent to provide the title compound as a white solid(0.280 g, 56%).

METHOD EXAMPLES Example A Bioassays on Green Peach Aphid (“GPA”) (Myzuspersicae) (MYZUPE.)

GPA is the most significant aphid pest of peach trees, causing decreasedgrowth, shriveling of leaves, and the death of various tissues. It isalso hazardous because it acts as a vector for the transport of plantviruses, such as potato virus Y and potato leafroll virus to members ofthe nightshade/potato family Solanaceae, and various mosaic viruses tomany other food crops. GPA attacks such plants as broccoli, burdock,cabbage, carrot, cauliflower, daikon, eggplant, green beans, lettuce,macadamia, papaya, peppers, sweet potatoes, tomatoes, watercress andzucchini among other plants. GPA also attacks many ornamental crops suchas carnations, chrysanthemum, flowering white cabbage, poinsettia androses. GPA has developed resistance to many pesticides.

Several molecules disclosed herein were tested against GPA usingprocedures described below.

Cabbage seedling grown in 3-in pots, with 2-3 small (3-5 cm) trueleaves, were used as test substrate. The seedlings were infested with20-5-GPA (wingless adult and nymph stages) one day prior to chemicalapplication. Four posts with individual seedlings were used for eachtreatment. Test compounds (2 mg) were dissolved in 2 mL ofacetone/methanol (1:1) solvent, forming stock solutions of 1000 ppm testcompound. The stock solutions were diluted 5× with 0.025% Tween 20 inwater to obtain the solution at 200 ppm test compound. A hand-heldaspirator-type sprayer was used for spraying a solution to both sides ofthe cabbage leaves until runoff. Reference plants (solvent check) weresprayed with the diluent only containing 20% by volume acetone/methanol(1:1) solvent. Treated plants were held in a holding room for three daysat approximately 25° C. and ambient relative humidity (RH) prior tograding. Evaluation was conducted by counting the number of live aphidsper plant under a microscope. Percent Control was measured by usingAbbott's correction formula (W. S. Abbott, “A Method of Computing theEffectiveness of an Insecticide” J. Econ. Entomol 18 (1925), pp.265-267) as follows.

Corrected % Control=100*(X−Y)/X

-   -   where    -   X=No. of live aphids on solvent check plants and    -   Y=No. of live aphids on treated plants

The results are indicated in the table entitled “Table 1: GPA (MYZUPE)and sweetpotato whitefly-crawler (BEMITA) Rating Table”.

Example B Bioassays on Sweetpotato Whitefly Crawler (Bemisia tabaci)(BEMITA.)

The sweetpotato whitefly, Bemisia tabaci (Gennadius), has been recordedin the United States since the late 1800s. In 1986 in Florida, Bemisiatabaci became an extreme economic pest. Whiteflies usually feed on thelower surface of their host plant leaves. From the egg hatches a minutecrawler stage that moves about the leaf until it inserts itsmicroscopic, threadlike mouthparts to feed by sucking sap from thephloem. Adults and nymphs excrete honeydew (largely plant sugars fromfeeding on phloem), a sticky, viscous liquid in which dark sooty moldsgrow. Heavy infestations of adults and their progeny can cause seedlingdeath, or reduction in vigor and yield of older plants, due simply tosap removal. The honeydew can stick cotton lint together, making it moredifficult to gin and therefore reducing its value. Sooty mold grows onhoneydew-covered substrates, obscuring the leaf and reducingphotosynthesis, and reducing fruit quality grade. It transmittedplant-pathogenic viruses that had never affected cultivated crops andinduced plant physiological disorders, such as tomato irregular ripeningand squash silverleaf disorder. Whiteflies are resistant to manyformerly effective pesticides.

Cotton plants grown in 3-inch pots, with 1 small (3-5 cm) true leaf,were used at test substrate. The plants were placed in a room withwhitefly adults. Adults were allowed to deposit eggs for 2-3 days. Aftera 2-3 day egg-laying period, plants were taken from the adult whiteflyroom. Adults were blown off leaves using a hand-held Devilbliss sprayer(23 psi). Plants with egg infestation (100-300 eggs per plant) wereplaced in a holding room for 5-6 days at 82° F. and 50% RH for egg hatchand crawler stage to develop. Four cotton plants were used for eachtreatment. Compounds (2 mg) were dissolved in 1 mL of acetone solvent,forming stock solutions of 2000 ppm. The stock solutions were diluted10× with 0.025% Tween 20 in water to obtain a test solution at 200 ppm.A hand-held Devilbliss sprayer was used for spraying a solution to bothsides of cotton leaf until runoff. Reference plants (solvent check) weresprayed with the diluent only. Treated plants were held in a holdingroom for 8-9 days at approximately 82° F. and 50% RH prior to grading.Evaluation was conducted by counting the number of live nymphs per plantunder a microscope. Pesticidal activity was measured by using Abbott'scorrection formula (see above) and presented in Table 1.

TABLE 1 GPA (MYZUPE) and sweetpotato whitefly-crawler (BEMITA) RatingTable Example Compound BEMITA MYZUPE 6a B B 6b D B 6c A B 6d D B 6e D BCompound 8.6 A A Compound 11.6 A A Compound 18.6 B B Compound 19.6 B B

% Control of Mortality Rating 80-100 A More than 0-Less than 80 B NotTested C No activity noticed in this bioassay D

COMPARATIVE EXAMPLES Example CE-5:3-Chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine

Attempted Decarboxylation with Sulfuric Acid:

3-Chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride(1.00 g, 2.50 mmol) was dissolved in warm sulfolane (12.5 mL). sulfuricacid (1.35 mL, 25.0 mmol) was added and the reaction mixture was heatedto 100° C. After stirring for 1 hour, LCMS indicated that the reactiondid not occur. The reaction was further heated at 130° C. for 2 hour, atwhich point LCMS indicated no change. Additional sulfuric acid (4 mL)was added and the reaction was heated at 150° C. for 2 hour, at whichpoint LCMS showed a new major peak that did not correspond to desiredproduct.

Attempted Decarboxylation with Palladium (II)Trifluoroacetate/Trifluoroacetic Acid:

3-Chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride(1.00 g, 2.50 mmol) was dissolved in a mixture of dimethylsulfoxide(0.625 mL) and N,N-dimethylformamide (11.9 ml). Trifluoroacetic acid(1.93 ml, 25.0 mmol) was added followed by the addition of palladium(II)trifluoroacetate (0.332 g, 1.00 mmol). The reaction was heated at 100°C. overnight, at which time LCMS indicated that a reaction had occurredbut no desired product had been formed.

It should be understood that while this invention has been describedherein in terms of specific embodiments set forth in detail, suchembodiments are presented by way of illustration of the generalprinciples of the invention, and the invention is not necessarilylimited thereto. Certain modifications and variations in any givenmaterial, process step or chemical formula will be readily apparent tothose skilled in the art without departing from the true spirit andscope of the present invention, and all such modifications andvariations should be considered within the scope of the claims thatfollow.

1. A process comprising reacting 3-hydrazinopyridine dihydrochloridewith glyoxylic acid to yield (E)-2-(2-(pyridin-3-yl)hydrazono)aceticacid (6a)


2. (canceled)
 3. A process comprising dehydrocyanating3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carbonitrile (6b) inthe presence of a base, to yield 3-(3-chloro-1H-pyrazol-1-yl)pyridine(5b)


4. A process comprising acylating3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine (5d) with acetic anhydride,in the presence of a base, to yieldN-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1c)


5. A process comprising condensing3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine (5d) with acetaldehyde andreducing to yield 3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-4-amine(1d)


6. A process comprising reacting (E)-2-(2-(pyridin-3-yl)hydrazono)aceticacid (6a) with methyl acrylate, in the presence of a chlorine source, aninorganic base, and a sub-stoichiometric amount of water, to yieldmethyl 3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate(6c)


7. A process comprising oxidizing methyl3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate (6c)with diammonium cerium (IV) nitrate (CAN) to yield methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d)


8. A process comprising saponifying methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d) to yield3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid (6e)


9. A process comprising hydrolyzing methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d) to yield3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid (6e)


10. A process comprising decarboxylating3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid (6e), in thepresence of copper (II) oxide, to yield3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b)

11.-15. (canceled)
 16. A compound3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carbonitrile (6b)


17. A compound methyl3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate (6c)


18. A compound methyl3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate (6d)


19. A compound 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid(6e)

20.-23. (canceled)
 24. A compound ethyl5-oxo-2-(pyridin-3-yl)pyrazolidine-3-carboxylate (Compound 18.6)


25. A compound ethyl3-chloro-1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate(Compound 19.6)